From 6d720f44f26a2eb851c787b3c70b149fd60e3cc0 Mon Sep 17 00:00:00 2001
From: Luke K <lkingland2038@gmail.com>
Date: Mon, 8 Jun 2020 04:59:31 +0000
Subject: [PATCH] example go templates for HTTP and CloudEvents

---
 templates/README.md                |  0
 templates/go/events/go.mod         |  5 ++++
 templates/go/events/handle.go      | 32 ++++++++++++++++++++++++++
 templates/go/events/handle_test.go | 32 ++++++++++++++++++++++++++
 templates/go/http/go.mod           |  3 +++
 templates/go/http/handle.go        | 13 +++++++++++
 templates/go/http/handle_test.go   | 37 ++++++++++++++++++++++++++++++
 7 files changed, 122 insertions(+)
 create mode 100644 templates/README.md
 create mode 100644 templates/go/events/go.mod
 create mode 100644 templates/go/events/handle.go
 create mode 100644 templates/go/events/handle_test.go
 create mode 100644 templates/go/http/go.mod
 create mode 100644 templates/go/http/handle.go
 create mode 100644 templates/go/http/handle_test.go

diff --git a/templates/README.md b/templates/README.md
new file mode 100644
index 00000000..e69de29b
diff --git a/templates/go/events/go.mod b/templates/go/events/go.mod
new file mode 100644
index 00000000..9b6de060
--- /dev/null
+++ b/templates/go/events/go.mod
@@ -0,0 +1,5 @@
+module function
+
+go 1.13
+
+require github.com/cloudevents/sdk-go/v2 v2.0.0
diff --git a/templates/go/events/handle.go b/templates/go/events/handle.go
new file mode 100644
index 00000000..c6c170d0
--- /dev/null
+++ b/templates/go/events/handle.go
@@ -0,0 +1,32 @@
+package function
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+)
+
+// Handle a CloudEvent.
+// Supported function signatures:
+//   func()
+//   func() error
+//   func(context.Context)
+//   func(context.Context) error
+//   func(cloudevents.Event)
+//   func(cloudevents.Event) error
+//   func(context.Context, cloudevents.Event)
+//   func(context.Context, cloudevents.Event) error
+//   func(cloudevents.Event, *cloudevents.EventResponse)
+//   func(cloudevents.Event, *cloudevents.EventResponse) error
+//   func(context.Context, cloudevents.Event, *cloudevents.EventResponse)
+//   func(context.Context, cloudevents.Event, *cloudevents.EventResponse) error
+func Handle(ctx context.Context, event cloudevents.Event) error {
+	if err := event.Validate(); err != nil {
+		fmt.Fprintf(os.Stderr, "invalid event received. %v", err)
+		return err
+	}
+	fmt.Printf("%v\n", event)
+	return nil
+}
diff --git a/templates/go/events/handle_test.go b/templates/go/events/handle_test.go
new file mode 100644
index 00000000..492e2ef3
--- /dev/null
+++ b/templates/go/events/handle_test.go
@@ -0,0 +1,32 @@
+package function
+
+import (
+	"context"
+	"testing"
+
+	"github.com/cloudevents/sdk-go/v2/event"
+)
+
+// TestHandle ensures that Handle accepts a valid CloudEvent without error.
+func TestHandle(t *testing.T) {
+	// A minimal, but valid, event.
+	event := event.New()
+	event.SetID("TEST-EVENT-01")
+	event.SetType("com.example.event.test")
+	event.SetSource("http://localhost:8080/")
+
+	// Invoke the defined handler.
+	if err := Handle(context.Background(), event); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// TestHandleInvalid ensures that an invalid input event generates an error.
+func TestInvalidInput(t *testing.T) {
+	invalidEvent := event.New() // missing required fields
+
+	// Attempt to handle the invalid event, ensuring that the handler validats events.
+	if err := Handle(context.Background(), invalidEvent); err == nil {
+		t.Fatalf("handler did not generate error on invalid event.  Missing .Validate() check?")
+	}
+}
diff --git a/templates/go/http/go.mod b/templates/go/http/go.mod
new file mode 100644
index 00000000..e66a0aa3
--- /dev/null
+++ b/templates/go/http/go.mod
@@ -0,0 +1,3 @@
+module function
+
+go 1.13
diff --git a/templates/go/http/handle.go b/templates/go/http/handle.go
new file mode 100644
index 00000000..5c192d6e
--- /dev/null
+++ b/templates/go/http/handle.go
@@ -0,0 +1,13 @@
+package function
+
+import (
+	"context"
+	"net/http"
+)
+
+// Handle an HTTP Request.
+func Handle(ctx context.Context, res http.ResponseWriter, req *http.Request) error {
+	res.Header().Add("Content-Type", "text/plain")
+	res.Write([]byte("OK\n"))
+	return nil
+}
diff --git a/templates/go/http/handle_test.go b/templates/go/http/handle_test.go
new file mode 100644
index 00000000..4b450dab
--- /dev/null
+++ b/templates/go/http/handle_test.go
@@ -0,0 +1,37 @@
+package function
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+// TestHandle ensures that Handle executes without error, returns 2000 and sets
+// and sets a content-type.
+func TestHandle(t *testing.T) {
+	var (
+		w   = httptest.NewRecorder()
+		req = httptest.NewRequest("GET", "http://example.com/test", nil)
+		res *http.Response
+		err error
+	)
+
+	// Invoke the Handler via a standard Go http.Handler
+	func(w http.ResponseWriter, req *http.Request) {
+		err = Handle(context.Background(), w, req)
+	}(w, req)
+	res = w.Result()
+
+	// Assert postconditions
+	if err != nil {
+		t.Fatalf("unepected error in Handle: %v", err)
+	}
+	if res.StatusCode != 200 {
+		t.Fatalf("unexpected response code: %v", res.StatusCode)
+	}
+	if res.Header.Get("Content-Type") == "" {
+		t.Fatal("Handler did not set a content type for the response")
+	}
+
+}